ANNALS OF GEOPHYSICS, 63, 1, SE106, 2020; doi:10.4401/ag-8175 Earthquakes and ghost towns in Sicily: from the Valle del Belìce in 1968 to the Val di Noto in 1693. The first stage of the virtual seismic itinerary through Italy ,1 2 1 Raffaele Azzaro* , Massimiliano Cascone , Alfio Amantia (1) Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Catania, Italy (2) Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Pisa, Pisa, Italy Article history: received April 7, 2019; accepted September 5, 2019 Abstract Destructive earthquakes leave traces not only on the physical landscape but also on human processes. Among the most devastating consequences is the abandoning of towns and villages, in favour of locations deemed safer. Abandoning a village and resettling in a new location, whether a gradual process or the result of a sudden traumatic situation, is an event of great historical, cultural and anthropological impact. It entails the loss of a piece of history or culture – local identity – and the more suddenly it happens, the more dramatic the after-effects. Italy has almost two hundred localities that have been abandoned for different causes (landslides, floods, volcanic eruptions, but also social or environmental reasons), some ninety of them owing to earthquakes. Sicily, a land of volcanoes and earthquakes, has several traces of former villages either in the form of fairly substantial ruins or even half-destroyed, which are usually located a few kilometres away from the new settlements. In this paper, we present the methodological approach developed in the framework of the EDURISK Project to enhance the awareness of seismic risk as an element of daily life; the case-study of the Valle del Belìce after the 1968 earthquakes represents the richness and complexity of this approach well. Following this rationale, in 2006, we published the first multimedia product devoted to Sicily based on the tools available at that time: a DVD-Rom hosting the interactive Quick Time™ Virtual Reality format. Today, multimedia technology is much more advanced and web- oriented, but the methodological approach is still valid. Keywords: Sicily, Ghost towns, Earthquakes. 1. Introduction Destructive earthquakes leave deep scars on the territory, both on the physical landscape (e.g. large landslides) and on society. One of the most striking effects is the abandonment of villages and towns, even important ones, in favor of new ones believed safer with respect to the causative event or also more suitable for the changed social- economic conditions [e.g. Camassi, 2004]. Abandoning a town and resettling the community in a new site, whether 1 Raffaele Azzaro et al. as result of a process over time or of a sudden traumatic situation, is an event of wide historical, cultural and anthropological impact [e.g. Teti, 2004]. Indeed, in many cases it leads to the loss of a piece of local history and culture, especially when the change is rapid. Abandoned settlements are therefore the most spectacular testimonies to the fragility of the territory. Better than any other evidence, they show the impact of a seismic event on the life of a community. For this reason, their rediscovery is a unique opportunity from a cultural standpoint to enhance the awareness of seismic risk as an element of daily life [Bitelli et al., 2000a]. This rationale has been developed in the framework of the EDURISK Project (Earthquake eDUcation: an investigative journey into seismic RISK reduction, www.edurisk.it), funded since 2002 by the Italian Civil Protection Department [Camassi et al., 2005; Pessina and Camassi, 2012]. One of the main tasks of the project was to prepare a series of virtual journeys through the traces left by past destructive earthquakes in Italy [Azzaro, 2012]. In this paper, we present the first interactive multimedia (DVD) created on a regional scale, devoted to the virtual navigation throughout the seismic itineraries of Sicily [Azzaro et al., 2006]. As a prototype for other earthquake-prone regions, it has been designed as a multidisciplinary tool to document features and effects of the earthquakes, their social impact and reconstruction dynamics; information on the seismic classification is also provided. In the following, the criteria and methodological approach applied in this work are described in detail together with some cultural aspects resulting from the critical reading of the materials. 2. Deserted settlements in Italy: a brief overview A detailed investigation on a wide range of historical sources and recent studies was the first step to obtain a preliminary inventory of abandoned settlements throughout Italy [Camassi, 2004]. As a result, nearly two hundred localities were recognized as having been abandoned for different natural causes including, in order of importance, landslides, floods, earthquakes and volcanic eruptions, but there are also situations determined by long-lasting effects due to environmental and anthropic reasons (Figure 1a). For example, the defensive position of the medieval villages on the top of hills was no longer necessary after the 17th century and new towns were established in better sites for trading and farming [Klapisch-Zuber, 1973]. One clue to such a process is the frequency, in the Italian territory, of place names tagged with “vecchio” or “antico” (old) or “nuovo” (new). Overall, some ninety settlements were abandoned as a consequence of earthquakes, although in a few cases this was not the sole cause. Traces of the ancient sites are of archaeological type, usually identifiable a few kilometres away from the new towns and visible in the form of more or less evident isolated remains or settlements in ruins (since the late 1800s). Most of them are located in Central and Southern Italy (Figure 1b), namely in regions prone to destructive earthquakes, especially in connection with the great seismic sequences occurring in 1703 in the Central Apennines, 1783 in Calabria and 1693 in Eastern Sicily (Figure 1c). Two very apparent spots of deserted localities appear at the extremities of the peninsula: the first in north-west Italy at the border with France, where the abandonment was caused by the M6.3 1887 earthquake; the second in Western Sicily as a consequence of the 1968 Valle del Belìce earthquakes. 3. Ghost towns in Sicily: a journey through time In Sicily, the case-studies regard very different situations, both from the historical viewpoint of the period concerned and the geo-anthropological features of the affected areas; in all, 17 sites which underwent total or partial resettlement have been identified (Figure 1d). In particular, six ghost towns are related to the “recent” 1968 seismic period in Western Sicily (namely Valle del Belìce) [Gangemi and La Franca, 1979], occurring in an area considered poorly seismic up until this date. The largest group of abandoned settlements (10 sites) is associated with the 1693 earthquakes, one of the main Italian seismic catastrophes that caused extensive destruction in the towns of Eastern Sicily (also known as Val di Noto) [Dufour and Raymond, 1994]. Finally, the case-study presented for North-eastern Sicily is unique since the abandonment is a consequence of the earthquakes devastating Southern Calabria in 1783 [Principe, 2001]. Linking the abandonment to the causative earthquake, we have grouped these ghost towns into three distinct macro-areas, namely the 1693 Val di Noto, 1783 Val Dèmone and 1968 Valle del Belìce (Table 1). 2 Earthquakes and ghost towns in Sicily Figure 1. (a) Location of the towns and villages abandoned in Italy as a consequence of natural phenomena and other anthropic causes. (b) Localities deserted following destructive earthquakes. (c) Distribution of M≥6.0 earthquakes according to the CPTI15 catalogue [Rovida et al., 2016]. (d) Ghost towns in Sicily; dates refer to the earthquakes responsible for the abandonment of the sites. In general, the deserted settlements presented here show heterogeneous characteristics also within the same group, firstly with respect to how they appear today. In the Valle del Belìce, in only a couple of cases, such as Poggioreale and Santa Margherita, is the field evidence still impressive, while at the other localities the remains are quickly disappearing despite the short time elapsed since 1968. This is largely due to the complete lack of preservation measures to counteract the theft of the few remains and the dismantling action of vegetation. Secondly, there is the different size of the settlements. These range from important towns such as Noto Antica - the old administrative capital of the wealthy Val di Noto from the Arab period till the 1693 earthquakes – to mountain villages, but also a few isolated ruins with a certain relevance from the historical and artistic points of view. 3 Raffaele Azzaro et al. Inhabitants Distance Deserted Coordinates Altitude New before from the District locality Lat - Long (m a. s.l.) settlement abandonment new site (km) Val di Noto (1693) Avola Vecchia 6000 36.9354 - 15.1085 400 4 Avola Syracuse Buscemi 2200 37.0834 - 14.8847 760 0,3 Buscemi Syracuse Calatabiano Vecchia 800 37.8292 - 14.9496 210 1 Calatabiano Catania Fenicia Moncada 1600 37.5408 - 14.9496 250 6 Belpasso Catania Licodia 3000 37.1548 - 14.6993 580 adjacent Licodia Eubea Catania Noto Antica 12000 36.9412 - 15.0237 409 7 Noto Syracuse Occhiolà 3000 37.2369 - 14.6230 480 7 Grammichele Catania Sortino Vecchia 6000 37.1535 - 15.0326 380 0,5 Sortino Syracuse Spaccaforno 8000 36.7908 - 14.9157 170 1 Ispica Ragusa Terravecchia 3000 37.0779 - 14.8025 770 3 Giarratana Ragusa Valle del Belìce (1968) Gibellina 5800 37.7880 - 12.9743 450 10 Gibellina nuova Trapani Montevago 3000 37.7072 - 12.9740 380 1 Montevago nuova Agrigento Poggioreale 2700 37.7917 - 13.0270 400 7 Poggioreale nuova Trapani Salaparuta 2800 37.7789 - 12.9887 385 5 Salaparuta nuova Trapani Santa Margherita 7000 37.6928 - 13.0267 420 0,3 Santa Margherita Agrigento Santa Maria del Bosco - 37.7132 - 13.2067 827 abandoned Palermo Val Dèmone (1783) Gioiosa Guardia 450 38.1512 - 14.9314 803 10 Gioiosa Marea Messina Table 1.